Relay



Sept. 5, 1933. J w BA 1,925,997

RELAY Filed May 18, 1932 IFE'TTIEF J1: se 'h In]. E arkham PatentedSept. 5, 1933 UNITED STATES PATENT OFFICE RELAY of Delaware ApplicationMay 18, 1932.

18 Claims.

This invention relates in general to electromagnetic relays of the typeadaptable for use in telephone practice or other places where relativelysmall values of current are used for op- 5 crating the relays, and theprincipal object of the invention is the provision of an electromagneticrelay in which the operation is extremely efiicient, which has a strongmagnetic circuit for operating larger spring loads, is simply and easilyadjusted, and is more sensitive and reliable in operation thanelectromagnetic relays have been heretofore.

It is a. further object of the invention to provide a relay having amagnetic circuit with only a single air gap in it thereby providing alow reluctance magnetic circuit path.

A further object resides in providing an electromagnetic relay in whichthe leakage flux between the core of the relay and the heel piece isreduced to a minimum.

In accordance with the above objects a number of features are containedin the electro magnetic relay of the invention, such as, a core and aheel piece which are placed edgea wise to each other so as to presentnarrow opposing surfaces and thereby considerably reduce the leakage ofthe magnetic flux flowing across the core and heel piece when the magnetcoil is energized; a large bearing pin on the heel piece for thearmature so that the air gap between the armature and the heel piece ispractically eliminated and at the same time provide a longer operatinglife for the moving part of the armature; and anadjustment of the heelpiece with respect to the core so that the armature may be properlypositioned opposite the end of the core and operate correctly in thedesired manner.

The invention is illustrated in the accompanying sheet of drawing which,together with the description discloses a preferred embodiment of theinvention. In the drawing, Fig. 1 shows a side elevation of anelectromagnetic relay according to the invention; Fig. 2 is a view ofthe same relay as seen from the bottom; Fig. 3 is a rear View of therelay; while Fig. 4 is a top View of the armature end of the relay. Fig.5 is a side elevation of a modification of the electromagnetic relay;and Fig. 6 is a top view from the armature end of the modified form ofrelay.

Referring now more particularly to Fig. 1 the relay comprises the usualcoil winding 1 wound on a spool which fits over the flat metal core r 2having a turned over end 3 at the armature end. A pair of mountingscrews 4 secure one end of Serial No. 612,058

the core 2 to the flat metal heel piece 5. The heel piece is arrangedparallel to the flat surface of the core 2 so that both present theirnarrow opposing edges to each other as is more clearly seen in the topview, Fig. 4. A portion 6 of the heel piece 5 is turned up and providesa means for suitably supporting the electromagnetic relay as a whole ona mounting frame. Another projection 7 of the heel piece 5 is turned upand arranged to serve as a mounting plate for a number of flexiblecontact springs 8 only a few being shown, and which are secured by meansof the pair of screws 9 in the projecting portion '7. A non-magneticarmature backstop 36 is also held in place on the projection 7 by thescrews 9. From the foregoing it will be seen that the heel piece member5 can be stamped and formed of a single piece of flat metal providedwith the projecting portions 6 and '7, resulting in a very economicalarrangement.

A flat magnetic armature 15, the general shape of which is more clearlyseen in Fig. 4, is pivoted to one end of the heel piece 5 by means of apair of projecting portions 17 and 18 extending from opposite sides andintegral with the armature 15. The armature 1-5 is formed at itssupporting end into a curved or semi-circular shape 16 more clearly seenin Figs. 1 and 3. A brass hearing pin 20 extends through the projectingpieces 17 and 18 and the heel piece 5 to -form a pivot point for thearmature 15. The projecting piece 18 has an armature lever 19 formedintegral with it and suitably cent so that it can engage the contactsprings 8 to operate the same when the armature is actuated. Acylindrical shaped iron pin 21 is riveted at one end to the heel piece 5directly below the semi-circular portion 16 of the armature 15. Thecrass bearing pin 20 extends through this iron pin and the arrangementis such that armature 15 in its operation rotates its semi-circularportion 16 about the metal pin 21 but without engaging it at any pointso that at all times a minimum amount of air space for the magnetic fluxto cross extends between these two members.

In most prior electromagnetic relays the struc ture usually comprised. acore of round or cylindrical shape and a flat heel piece which togetherwith the armature completed the magnetic circuit. The heel piece isusually arranged so that one end of it is fastened to one end of theround core while the armature is pivoted on the other end and it has itswidest surface arranged parallel to and adjacent the core of the relay.When the coil is energized a magnetic flux is created which extends overa magnetic circuit path including the core, heel piece, and the armaturein order to operate the same. With this arangement of parts, however,considerable flux leakage takes place between the core and the widesurface of the heel piece, because the large surfaces between the twoand their proximity presents a comparatively low reluctance path for theflux to leak across. This leakage consequently reduces the amount offiux flowing through the armature and the core and considerably reducesthe pull upon the armature. By providing a fiat core and a flat heelpiece in which the widest edge is parallel with the fiat surface of thecore and in which the narrow edges of the core and heel piece areadjacent to one another according to the invention a smaller opposingsurface is presented between the two so that the flux leakage is verysmall and a relatively high reluctance magnetic path exists betweenthem. As a result practically all of the flux flows from the corethrough the heel piece to the armature without any great loss, renderingthe pull upon the armature very strong and powerful and the operation ofthe relay more eflicient, permitting the operation of greater contactspring loads than has been heretofore possible.

A further reason for the great efiiciency of the magnetic circuit of therelay described, resides in the pivoting arrangement of the armature. Informer types of electromagnetic relays the armature was usually pivotedon the heel piece between two projecting ear members on the heel piecethrough which a brass pivoting pin projected and engaged other earmembers on the armature. This arrangement, it is seen, introduced aconsiderable air gap and high reluctance magnetic path over which themagnetic circuit was completed and thereby reduced the magnetic pullupon the armature even though the other parts of the magnetic circuitpath, including the heel piece and the core, were as eflicientlyconstructed as possible. The invention overcomes this diificulty byproviding a cylindrical iron pin 21 fastened to the heel piece 5 and anarmature 15 which is provided with a semicircular portion 1.6 snuglyfitting over a portion of the surface of the pin 21 and pivoted to heelpiece 5 by the brass pin 20. A small space is provided between the pin21 and the bottom surface of the circular portion 16 of the armature 15so that they do not frictionally engage. With this arrangement a largearea or surface is presented in the magnetic circuit path so that themagnetic flux flowing from the core 5 extends over the whole surface ofthe pin 21 across the minute air gap between the pin and the circularportion 16 of the armature which has a large surface opposingpractically half of that of the roller 21, and a very low reluctance magnetic path, therefore, exists so that the pull upon the armature 15 isvery powerful against the core 3.

When the relay after having been operated deenergizes, the armature 15is restored to normal due to the pressure of the operated contactsprings 8 upon the end of the armature lever 19. This pressure overcomesany tendency of the armature 15 to stick against the bent over end 3 ofthe core 2 due to residual magnetism which may exist in the decayingmagnetic circuit. If desired a small brass shim may be inserted over thebent over portion 3 of the core 2 as is the usual practice.

In order to provide a ready means for adjusting the stroke of thearmature 15 against the bent over portion 3 of the core 2 and in orderto adjust it so that it lies flat against the core piece 3 when fullyattracted, an arrangement is provided according to the invention forconveniently doing this. One of the mounting screws 4 which secure theheel piece 5 directly on one end of the core 2, rides in a slot 25 inthe heel piece so that by merely loosening the screws 4 and rotating theheel piece 5 about a pivot point formed by the right hand one of themounting screws 4, the heel piece 5 may be slightly rotated closer orfarther away from the armature end of the core 2 until the properadjustment of the armature 15 with respect to the core portion 3 isobtained. When this is done both screws 4 are tightened.

To avoid friction and also magnetic attraction or sticking of the earmembers 1'7 and 18 of the armature 15 against the pin 21 and heel piece5, a small brass washer is inserted on the pivoting pin 20 adjacent theear members as shown.

In Figs. 5 and 6 a modification of the invention is disclosed. The coil1, core 2, and bent over portion 3 of the core 2, together with the heelpiece 5, extension 6 for mounting the relay and the extension 7 forsupporting the set of contact springs 8, are all of the sameconstruction as Fig. 1. A slightly different armature adjustment,however, is provided in that the screws 4 for supporting the core 2 onthe heel piece 5 engage slotted holes 25 so that the core 2 may be movedcloser or farther away from the armature 15 in order to position itproperly on the extended turned over portion 3 of the core.

In the modification shown in Fig. 1 the semicircular portion 16 of thearmature 15 only partially encircles the iron pin 21 attached to theheel piece 5, but in the modification shown in Fig. 5, however, thearmature 15 is formed with a cylindrical iron tube 34 on its rear end.An iron bearing pin 30 fits inside of the tube 34 of the armature andserves as a bearing for the same. This bearing pin 30 is immovably andrigidly attached to the heel piece 5 by means of a screw 31 whichthreads into the end of the pin 30. An iron washer 32 fits under thescrew 31, while brass washer 33 fits between the end of the tube portion34 and the heel piece 5 in order to prevent the armature from stickingto the heel piece when the magnetic circuit is completed. The armaturelever 19 is securely attached as by riveting to the end of the tube 34of armature 15 and is keyed to it as shown so that it does not turnrelative to the armature. Due to the fact that the tube portion 34 ofthe armature 15 completely surrounds the iron bearing pin 30 the air gapusually adjacent these two surfaces is practically eliminated as a largesurface between them is always in direct contact with the bearing pin.When the flux flows the reluctance of the magnetic circuit at this pointis very low and the full flow traverses the magnetic circuit without anyloss. As seen by the dotted lines in Fig. 5 the armature bearing pin 30carrying the armature 15 is adjustable lengthwise of the heel piece 5 bymerely loosening the screw 31 and sliding it up or down in the slot 35in the heel piece and then tightening the same again. This moves thearmature 15 closer or farther away from the turned over portion 3 of theheel piece 2 and provides an adjustment in addition to that provided bythe mounting screws 4 sliding in slots 25 in the core 2.

It will be understood that while the armatures in each of themodifications have been shown as pivoted to the side of the heel piece 5it will be appreciated that the construction contemplates an arrangementin which the armature may be pivoted on opposite sides of the heel piece5; that is, a slot may be cut in the armature and the heel pieceaccommodated therein. This would place the core 2 and heel piece 5directly opposite and parallel to one another instead of to one side asshown in the drawing.

What is claimed is:

1. In an electromagnetic device, the combination of a fiat core and heelpiece, respectively, set edgewise with respect to each other togetherwith means for adjusting them relative to each other.

2. In an electromagnetic device, the combination of a flat core and heelpiece in which the narrow edges are adjacent one another so as to reducethe flux leakage between them together with means for supporting saidcore on said heel piece in an adjustable manner.

3. In an electromagnetic device, the combination of a core and a heelpiece in which each is constructed with wide edges and narrow edges andin which one of the narrow edges of each is placed adjacent one of thenarrow edges of the other and means for adjustably supporting the coreon the heel piece.

4. In an electromagnetic device, the combination of a core and heelpiece each having wide and narrow edges and in which only their narrowedges are adjacent one another and in which the core is supported on theheel piece, together with means for varying the separation between them.

5. In an electromagnetic device, the combination of a flat core and aflat heel piece arranged with the flat sides in approximately the sameplane so as to reduce to a minimum the leakage of flux between them, anarmature mounted on said heel piece, and means for adjustably supportingsaid core on said heel piece so the position of the armature withrespect to the core may be varied.

one end of the core for rotatably supporting the heel piece thereon soas to move the heel piece closer or farther away from the armature endof the core and thereby adjust the position of the armature with respectto the core.

8. In an electromagnetic device, a core, a heel piece having an armaturepivoted opposite one end of said core, said heel piece rotatablysupported on the other end of said core so that the position of thearmature with respect to the core may be varied.

9. In an electromagnetic device, a flat core, a flat heel piece havingan armature pivoted opposite one end of said core, said heel piecearranged with the flat side substantially paralel to the flat side ofsaid core and rotatably supported on one end thereof so as to move thearmature end of the heel piece closer or farther away from the core andthereby vary the position of the armature with respect to the core, andmeans for holding said heel piece in its adjusted position.

10. In an electromagnetic device, a core, a heel piece secured to oneend of said core, an armature on said heel piece opposite the other endof said core, a magnetic pin secured to said heel piece for pivoting thearmature opposite the end of the core, said armature having a portionenclosing but not in engagement with said pin to present a large surfacefor the flow of magnetic flux between said pin and armature.

11. In an armature pivoting arrangement, a heel piece, a magnetic pinsecured to said heel piece, an armature pivoted only at the ends of saidpin, and an extended portion on said armature conforming to the shape ofand rotatable about said pin but not in engagement therewith.

12. In an armature pivoting arrangement, a heel piece, a magnetic pinsecured to said heel piece, an armature pivoted to said magnetic pin,and a curved extension on said armature rotatable about said pin whensaid armature is moved but without engaging it at any point.

13. In an armature pivoting arrangement, a heel piece, a circular pinsecured to said heel piece, an armature pivoted only at the ends of saidcircular pin, and a curved extension on said armature conforming to theshape of and rotatable about said circular pin without engaging the sameat any point.

14. In an armature pivoting arrangement, a heel piece, a circularbearing pin mounted on said heel piece, an armature pivoted to saidbearing pin, and a semi-circular portion on said armature partiallyencircling said bearing pin and rotatable thereabout when said armatureis operated without coming into contact with it at any point.

15. In an armature pivoting arrangement, a 115 heel piece, a magneticbearing pin secured to said heel piece, and an armature provided with anopening through which said bearing pin extends so that said bearing pinis completely surrounded by said armature.

16. In an armature pivoting arrangement, a heel piece, a bearing pinsecured to said heel piece, an armature provided with an enlargedportion having an opening therein through which said bearing pinextends, said enlarged portion 125 of the armature completelysurrounding said bearing pin and engaging it at all points.

17. In an armature pivoting arrangement, a heel piece, a bearing pinrigidly secured to said heel piece, an armature, an enlarged circular130 bearing portion on said armature through which said bearing pinextends so that it engages with it over its whole surface when thearmature is operated, and means for adjusting the position of saidbearing pin on said heel piece.

18. In an armature pivoting arrangement, a heel piece, an armaturehaving a circular por tion provided with an opening, a magnetic bearingpin secured to said heel piece and extending through the opening of saidcircular portion of the armature to serve as a pivot for the same, saidbearing pin and circular portion presenting large surfaces in contactwith each other, and a non-magnetic washer between said heel piece andthe end of said circular portion to prevent .I'c' the armature fromsticking to the heel piece due to residual magnetism.

JOSEPH W. BARKHAM.

